This paper descibes version 2.0 of {\bf jerasure}, a library in C++ that supports
erasure coding in storage applications.  In this paper, we describe
both the techniques and algorithms, plus the interface to the code.
Thus, this serves as a quasi-tutorial and a programmer's guide.

Version 2.0 of jerasure is written in C++, uses a new object-oriented interface, adds generalized EVENODD and generalized RDP to the library, supports multi-threaded coding, and includes two new example applications.
